Materials used in forming golf ball covers, such as balata, SURLYN®, and urethane elastomer, suffer from scratching, abrasion and shear produced by multiple oblique hits by a golf club. It is known that coatings can be applied to the surface of golf balls to increase the abrasion resistance of the coated surfaces but the results achieved with the use of such coatings have not entirely met the requirements of the golfing public. Thus, there is a need to improve the scratch resistance of such coating materials.
More than five hundred million golf balls are produced each year. Most of these balls have covers molded from the ionomeric resin SURLYN® or its counterparts and, to a lesser extent, balata (i.e., trans polyisoprene) and polyurethane. Conventionally, coating compositions are applied to the ball surface to protect the ball, the identifying indicia and any paint layers, and to add a pleasing appearance to the ball due to their high gloss. Typically such coatings comprise a clear primer coat and a clear top coat, and for certain applications a single top coat may suffice. The primer layer is applied to promote adhesion or to smooth the surface roughness before the top coat(s) are added to the golf ball. Coating compositions are generally free of pigmentation and are water white. However, they may contain small amounts of dye, pigment, and optical brighteners so long as they still allow for a bright ball cover. In golf balls of the type described above, the various identifying indicia may be applied either directly upon or alternatively upon the cover, the primer coat or the top coat.
Coating composition materials are well known in the art. Generally, they consist of urethanes, urethane hybrids, polyesters and acrylics. In particular, a cured polyurethane top coat is most widely used as a protective coating composition material. Polyurethane systems are typically either “one component” or “two component” systems.
U.S. Pat. No. 5,820,491 to Hatch et al., incorporated herein by reference in its entirety, relates to a polyurethane topcoat composition for golf balls comprising at least three components: (a) a polyol component, (b) an isocynate component, and (c) a hydroxyl functional, polyether-modified polysiloxane copolymer.
U.S. Pat. No. 6,596,837 to Hogge et al., incorporated herein by reference in its entirety, relates to golf equipment having a coating comprising (a) a reactive component A of a polyol, (b) a reactive component B of an isocyanate, (c) a colloidal silica, (d) a coupling agent to react with the colloidal silica, and (e) a solvent.
U.S. Pat. No. 6,657,001 to Anderson et al., incorporated herein by reference in its entirety, relates to coating compositions comprising (a) one or more polysiloxanes having at least one reactive functional group, (b) at least one reactant having one reactive functional group, and (c) a plurality of particles selected from inorganic particles and composite particles. However, the coating composition according to this reference is used only as automotive coatings, and the use of the composition on golf equipments is not taught or suggested in this reference.
There remains a need for scratch-resistant coating compositions for golf equipment comprising at least one polysiloxane having at least one functional group, at least one reactant having a functional group that is reactive to the at least one functional group of the at least one polysiloxane, and a plurality of particles such as inorganic, organic or composite particles, such that these compositions may be applied to golf equipment, in particular golf balls, range balls, golf clubs, golf shoes, drive heads, and golf bags, for improving the scratch resistance of the coated surfaces.